There are literally millions of freeware batch renaming apps - a quick
google chucks up this one which includes the ability to add/change
extensions on your files:
On 9 Jun 2003 09:56:38 +0100, Dirk Müller <Kraweel at web.de> wrote:
>We switched fro Mac to WinXP although converting the licence form Mac
>to PC is extremly expensive!!!!
>To import your old Mac files you habe to add the new WinXP-Version
>extension manualy. A lot of handwork because I could not find a
>software like filetyper (mac) to do the job in a kind of batch
>conversion on the pc.